1. Field of the Invention
The present invention relates to communications; more specifically, wireless communications.
2. Description of the Related Art
Previously, resource management and channel allocation on the uplink or reverse link (RL) has been treated primarily as a xe2x80x9cdistributed controlxe2x80x9d problem. In other words, a Base Station (BS) did not control the operations by assigning service order priorities. However, the BS did supervise access to the reverse link and monitor operations via slow or fast power control. For example, in CDMA 2000-1x systems, each mobile requested a reverse link channel at a specific rate. The BS monitored the interference patterns and determined whether to admit the user or not. Once the user was admitted at a chosen rate, the BS monitored the subsequent transmissions via fast power control. Another example of reverse link access and control can be found in 1xEV-DO systems. In these systems, every mobile began to transmit autonomously beginning with the lowest rate in the rate set. At every subsequent transmission, each mobile autonomously doubled its data rate. The base station continued to monitor the channel via power control. If the aggregate received power at the BS or the interference to each user exceeds a predefined threshold, the BS ordered all mobiles to reduce their data rates. Due to the autonomous nature of the transactions, this resulted in an inefficient data communications on the uplink between mobile stations and base stations.
One embodiment of the present invention provides efficient data communication in wireless communication systems by providing centralized control of data communications, such as packet switched services, over the uplink channel (mobile station (MS) to base station (BS)). A multiple access protocol is used where packet data mobile stations make requests for uplink channel resources. The request messages transmitted by the MSs inform the BS of service parameters. Examples of such service parameters are available transmit power at the MS, the amount of data to transmit and Quality of Service (QoS). The BS then processes the received request messages and performs interference management calculations to determine the portion of the BS""s receive power budget that can be allocated to the data user requesting service. These calculations are used to control the amount of interference seen at the base station, to assign a data rate to the user and to aid scheduling algorithms in computing service order priorities. Any scheduling algorithm may be used; for example, scheduling may be based on the amount of data to be transmitted, the age of the data or the service priority associated with the mobile station. The interference control is used to prevent the occurrence of catastrophic levels of interference while maximizing the utilization of resources on the uplink.
This method is useful in wireless communication systems such as Code Division Multiple Access (CDMA) systems, which serve a mixture of traffic classes; for example, voice services and data services. The method is particularly useful with respect to the packet data component of the overall traffic and serves to efficiently utilize the uplink channel while striking a balance between minimizing aggregate channel interference and improving user level quality of service (QoS).